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DISPLAYING POSTS TAGGED: orthoptera (2)

Prickly Katydids, or Spiny Tree Crickets, occur from the rainforests of northern New South Wales to Iron Range in Far North Queensland. There are four species of Prickly Katydids but the most common is Phricta spinosa. It has the rather long official common name of Giant Spiny Forest Katydid and is found from Innisfail to Cooktown. Those that know and love this species simply call it Phricta.

During the day, Phricta sits motionless on bark or amongst twigs with its legs held out straight where it is remarkably well camouflaged. Some bird species, particularly Black Butcherbirds, move up and down tree trunks trying to disturb the insects so they will give themselves away. When threatened, Phricta will point its back legs skyward, revealing rows of sharp spines and red patches at the bases of the legs. These red patches appear to discourage predators.

The legs of this adult male bear the black and orange markings of its startle display.Image: Patrick HonanSource: Patrick Honan

Adults have a body length of 10cm or so, and their highly sensitive antennae may be three times that length. Adults are normally found high in the rainforest canopy, but after mating, the female glides to the ground to lay her eggs in the soil.

An adult female pushes her abdomen into sandy soil to deposit a batch of eggsImage: Patrick HonanSource: Patrick Honan

The young Phricta feed low in the understorey on the constant 'rain' of flowers and buds from above.

A young nymph feeding on a fallen flower bud.Image: Patrick HonanSource: Patrick Honan

Phricta moult several times before reaching adulthood. Moulting takes place during the first part of the night and they are very vulnerable to predators at this time. The elongated antennae may take a long time to withdraw fully from the old skin.

Phricta moulting at night.Image: Patrick HonanSource: Patrick Honan

The colours of juvenile Phricta are variable and help camouflage them against tree trunks and lichen-covered bark.

Juvenile Phricta are often beautifully patterned with greens and browns. The budding wing pads can be seen between the spines of the legs and thorax.Image: Patrick HonanSource: Patrick Honan

A lichen-coloured specimen with a radically different colour pattern to other juvenile Phricta.Image: Patrick HonanSource: Patrick Honan

After reaching adulthood, Phricta can be found higher in the canopy, feeding on the young leaves of trees and shrubs. On particularly windy or stormy nights, they will move down into the lower canopy or into tree holes to shelter from the weather.

The long, sword-like ovipositor is visible at the end of this juvenile female's abdomen. Her oval-shaped 'ear' can also be seen just below the 'knee' of her right foreleg.Image: Patrick HonanSource: Patrick Honan

Like most katydid species, male Phricta call loudly to attract females in the rainforest at night, a sound familiar to people who frequent these forests. Females possess an auditory tympanum (or ear) on their forelegs to pick up the call.

Phricta are attacked by owls and other predatory birds, as well as honeyeaters and brush turkeys. They are also host to parasitic mites, which gather sometimes in large numbers on the top of the thorax. The effects of these mites on the insects are not known.

Phricta can be seen in the 'Diversity' display in Bugs Alive! at Melbourne Museum. Despite being very common and widespread in North Queensland rainforests, this species was not described scientifically until 2005, an indication of how much is still to be discovered and catalogued by science.

Further reading:

Rentz, D., 1996, Grasshopper Country: the Abundant Orthopteroid Insects of Australia, University of New South Wales Press, Sydney, 284pp.

Prior to becoming a keeper with the Live Exhibits team at Melbourne Museum, my knowledge of grasshoppers was quite limited. Locusts were probably the type of grasshopper of which I was most aware, due to their high numbers during the warmer months. They are also responsible for the must-have car fashion accessory adorning the front of vehicles, in the form of flywire to stop cars from overheating. In truth, locusts are just one of an estimated 700 species of grasshopper in Australia.

The Common Toad Hopper (Buforania crassa) is an inquisitive creature.Image: David PaddockSource: Museum Victoria

Live Exhibits keeps many different types of grasshoppers and I am quite intrigued by them all, but the species which first caught my attention was the Common Toadhopper (Buforania crassa) from Central Australia. They are not particularly big - females are approximately 60mm long and males 40 mm long - and contrary to their name they rarely hop or jump, preferring to walk around. They have been described as an inquisitive grasshopper and that is what drew me to them. As with pets at home, if you are looking after an animal and you buy it a new toy or feed it a new food then you hope that they will enjoy it or get a reaction from it. I found that not too long after I added food they would be on it or in it. This included pollen, orthopteran mix (made up of muesli, fish flakes and other ingredients), and various forms of foliage, such as abelia, emu bush, acacia, and callistemon. You soon find out that they have their favourites - I would say that callistemon is in the top two.

Common Toad Hopper (Buforania crassa) eating callistemon, one of its favourite foods.Image: David PaddockSource: Museum Victoria

Like most grasshoppers, Common Toadhoppers use camouflage to hide from predators. As you can see from the picture, once they are perched on a rock or stick during the daylight hours they can be very difficult to see. If they are brought up on a light sand substrate then their colours will reflect that.

Common Toadhoppers are masters of camouflage. Their colours can vary depending on what colour substrate they are brought up on.Image: Patrick HonanSource: Museum Victoria

Their reproductive cycle is very interesting. Grasshoppers generally breed in the summer months with the male perching on the female's back, either mating or guarding her from other males. The female then deposits her eggs in the soft sand and plugs them with a foamy substance. Our toadhopper populations here at Melbourne Museum vary seasonally and in some enclosures we currently have none at all, but we can see where females have deposited their eggs. Grasshopper eggs are good at withstanding drought periods. Normal incubation time for Common Toadhoppers is 1-3 months but it can be as long as 1-2 years, the eggs simply waiting for the right conditions. We can recreate those conditions, simulating warmer days with longer heat and light periods, and heavy rain through flooding the enclosures with water. Then hopefully not too long afterwards, little toadhopper nymphs will appear and even though they may not live up to the second part of their name, these grasshoppers certainly love eating grass.

A young Common Toadhopper.Image: Alan HendersonSource: Museum Victoria

In the meantime, come along to Melbourne Museum and visit our male Common Toadhopper, featured in the arid section of our Habitats display in Bugs Alive!.

Toadhoppers are in the arid habitat display in Bugs Alive!.
Image: David PaddockSource: Museum Victoria

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